FIG. 1 illustrates a typical pair of transverse flux inductors 102a and 102b with fixed transverse lengths between which an electrically conductive strip or slab material 90 (shown as a partial strip) moves in an industrial process, for example, annealing of the material or evaporating a solvent in a coating deposited on the material by electric induction heating of the material. Electrical connectors such as bus bars 102a′ and 102a″ (with 102a″ hidden behind electrical insulator 104a in the figure) are connected to opposing adjacent ends of inductor 102a and bus bars 102b′ and 102b″ (102b″ hidden behind electrical insulator 104b) are connected to opposing adjacent ends of inductor 102b. The bus bars in this example provide the means for electrical interconnection of transverse flux inductors 102a and 102b to one or more alternating current (AC) power supplies 106 that supply AC power to the inductors which generates a magnetic flux field around the inductors as represented by typical flux lines 108 with conical arrows 108a illustrating an instantaneous direction of the generated flux vectors when the inductors 102a and 102b are connected in a series electrical circuit with power supply 106 and arrow 109 illustrates corresponding instantaneous direction of AC current flow through inductor 102a. Arrow 91 indicates the corresponding instantaneous direction of typical induced heating current loops 91a′ and 91a″ in material 90. For orientation purposes herein the X-direction (and arrow) is referred to as the longitudinal, or longitudinal direction, of the material as it passes between the inductors and the material's edge-to-edge (93a to 93b) distance is referred to herein as the transverse, or transverse width, of the material and the pair of transverse flux inductors with reference to the indicated Cartesian coordinate system in the figures for a three-dimensional space (X being the longitudinal direction of travel of the material between the pair of transverse flux inductors; Y being the direction of the transverse, or transverse width, of the material and the pair of transverse flux inductors; and Z being the direction of vertical separation between the pair of transverse flux inductors).
When fixed-width transverse inductors are used, different fixed-width transverse inductors must be used to inductively heat materials having different transverse widths. For example fixed-width transverse flux inductor 202a shown transversely over material 92 with material width MW1 in FIG. 2(a) has a suitable transverse length IW1 to heat material 92 between transverse material edges 92′ and 92″ as it passes below inductor 202a when inductor 202a is paired with another transverse flux inductor (not shown in the figure) under material 92 and fixed-width transverse flux inductor 302a shown over material 94 with smaller material width MW1 in FIG. 2(b) has a suitable smaller transverse length IW2 to heat material 94 between transverse material edges 94′ and 94″ as it passes below inductor 302a with inductor 302a is paired with another transverse flux inductor (not shown in the figure) under material 94. In industrial applications a preferred transverse flux induction heating line has a single pair of adjustable-length transverse inductors to accommodate various widths of strip or slab materials. Typically this is accomplished by making at least a section of the physical non-flexible inductors variable in length, for example, one inductor physical segment retracting into or out of another inductor segment. For example, in U.S. Pat. No. 4,751,360 each of the pair of transverse flux inductors have a pair of straight sections with portions extending transversely to the material passing between them and curved sections that can be adjusted in position adjacent to the edges of the material to inductively heat materials of variable transverse widths.
It is one object of the present invention to provide an adjustable pairs of transverse flux inductors that can be adjusted for inductively heating materials of different widths without sectionalized variable physical lengths of inductor sections.
It is another object of the present invention to provide an adjustable pairs of transverse flux inductors where the transverse flux inductor is formed from a pair of flexible cables and at least one of the pair of flexible cables is adjustable in position to change the transverse width of the inductor and optionally the pole pitch of the inductor.
It is another example of the present invention to provide pairs of transverse flux inductors for independently tracking either one or both of the opposing edges of a material passing between the adjustable pair of transverse flux inductors where at least one of the pair of flexible cables is adjustable in position.